This invention relates to bedding units and to springs which are used in such units.
Traditionally, box spring units have been manufactured of many helical coils which support an upper deck on a lower frame member. More recently, many manufacturers have adopted a construction which, in lieu of coil springs, utilizes nonspiral formed wire springs which have horizontal torsion bars with opposite ends connected to upwardly and downwardly inclined connector bars. Examples of bedding units manufactured with formed wire springs are classified in U.S. Class 5, Subclasses 247 and 255.
In my earlier U.S. patent application Ser. No. 532,137, filed Sept. 14, 1983, now U.S. Pat. No. 4,559,654, a number of improved springs are disclosed and claimed. These springs represent significant advantages with respect to the versatility of spring placement, the manner in which the deflection of the springs was limited, and the general characteristics which made the springs desirable in bedding units.
The invention described in this application has many of the attributes of the springs disclosed in the aforementioned U.S. patent application Ser. No. 532,137 now U.S. Pat. No. 4,559,654. Further, this specification discloses a number of variations, modifications and improvements.
In one respect, the springs described in this specification are particularly well suited for the construction of bedding units which have frames with transverse metal slats. The invention presents different foot configurations which are effective to attach the springs to the frame and provide for proper balance and load distribution.
In another respect, the invention described in this specification represents an improvement to the previously disclosed devices in that the upper portion of a spring may have three transverse bars rather than two, and the center longitudinal bar can be formed of two sections which are on opposite sides of the central transverse bar and are directed toward the midportions of the end transverse bars. This configuration is desirable because it provides for greater versatility. The central transverse bar can be connected to a longwire of the grid in a balanced condition, and the sections of the center longitudinal bar can be connected to the crosswires of the grid.
According to another disclosed feature, the deflection limitations and/or the effectiveness of a spring can be varied. These effects can be produced by a deflection limiting member which is formed of wire and is attached to two spaced apart locations on the spring.
Among the many objects of this invention are to provide springs in bedding units which are suitable for their intended purposes, reasonably priced, and durable.